The purpose of this study is to collect further data for safety and feasibility for the use of the medical device OncoSorb® in clinical routine for the treatment of patients with solid metastatic cancer entities who have failed standard therapies. OncoSorb® device is intended to specifically adsorb three soluble receptors (sTNF-R1, sTNF-R2 and sIL-2R α), which are known to inhibit the natural immune response of cancer patients mediated via tumor necrosis factor α (TNF- α).